Castanea sativa means the plant that in detail is called Castanea sativa Mill. (synonyms: Castanea vesca Gaertn., Castanea vulgaris Lam.). “Mill.” denotes the nomenclature system used.
Castanea sativa (in the following text sometimes abbreviated as Castanea) belongs to the family Fagaceae. Common names for Castanea sativa are sweet chestnut and Spanish chestnut.
The use of chestnut leaves against complaints affecting the respiratory tract, such as bronchitis, cough, and disorders affecting the legs and the circulation is known. Like other tannin-containing drugs, chestnut leaves can be used as an astringent (Bundesanzeiger no 76, dated Apr. 23, 1987).
Antibacterial and allelopathic activity of extracts of Castanea sativa leaves is known (BASILE A., SORBO S., GIORDANO S., RICCIARDI L.; FERRARA S., MONTESANO R., CASTALDO COBIANCHI R., VUOTTO M. L., FERRARA L., “Antibacterial and allelopathic activity of extract from Castanea sativa Mill. Leaves”, FITOTERAPIA, volume 71, pages 110 to 116, published in 2000). In this publication the following is disclosed: Following the extraction of Castanea sativa leaves with an aqueous solution of sulfuric acid (pH 3.0), the ethyl acetate soluble fraction was tested for its antibacterial and allelopathic activity. The extract was shown to have pronounced antibacterial effects against seven of the eight strains of Gram-positive and Gram-negative bacteria used (MIC in the range of 64-256 microg/ml and MBC in the range of 256-512 microg/ml) (MBC=Minimum Bactericidal Concentration, MIC=minimal inhibiting concentration). The active fraction was analysed by TLC (thin layer chromatography) and HPLC showing the presence of rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol. Standards of the identified flavonoids were tested against the same bacterial strains. The highest activity was shown by quercetin, rutin and apigenin. The allelopathic effect was tested against Raphanus sativus seed germination. The extract, quercetin, rutin and apigenin caused a decrease in the percentage of seed germination and root and epicotyl growth.
The following documents of the state of the art describe the constituents that are contained in the leaves of Castanea sativa. 
According to Wichtl et al. (Wichtl M, Bisset in Herbal drugs and phytopharmaceuticals: a hand book for practice on a scientific basis, NG CRC PRESS, 1994, page 566) the leaves of Castanea sativa contain ca. 9% tannins whose nature is not precisely known (both gallic and ellagic acids have been detected), flavonoids especially quercetin derivatives, triterpens e.g. ursolic acid and ca. 0.2% vitamin C.
According to Wagner et al. 1996 (Wagner H., Bladt S. in Plant drug analysis, A thin Layer Chromatography atlas (2nd edition), Springer Verlag, 1996, page 384), the main constituents of Castanea sativa leaves are rutin, isoquercitrin, astragalin (e.g. kaempferol-3-O-glucoside), quercetin galacturonide, O p-coumaroyl quinic acid, saponins and fructose.
Kaempferol 2G-coumaroylrutinoside has been isolated from Castanea sativa (according to “Chapman, CD rom phytochemical dictionary”).
According to Basile et. al. (BASILE A., SORBO S., GIORDANO S., RICCIARDI L., FERRARA S., MONTESANO R., CASTALDO COBIANCHI R., VUOTTO M. L., FERRARA L., Antibacterial and allelopathic activity of extract from Castanea sativa Mill. leaves, FITOTERAPIA, volume 71, pages 110 to 116, published in 2000) after hydrolysis the main constituents of Castanea sativa leaves are rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol.
According to “Duke chemical data base” (a phytochemical and ethnobotanical data base), the main constituents of Castanea sativa leaves are betulin (1000 ppm), caffeic acid, ellagic acid, fat (81 000 ppm), gallic acid, hamamelose, kaempferol, pectin, protein (80 000 ppm), quercetin and tannin (90 000 ppm).
According to Romussi et. al. (ROMUSSI G., MOSTIN M., Nebenflavonoide der Blätter von Castanea sativa Mill. 3. Mitteilung: Über Inhaltsstoffe von Cupuliferae CIARALLO G. PHARMAZIE, volume 36, page 718, 1981), the main constituents of the leaves of Castanea sative are narcissin (synonym: Isorhamnetin 3-beta-rutinoside) and helichrysoside (synonym Quercetin, 3-O-beta-D-(6″O-p-coumaroyl)-glucopyranoside).
According to Marsili et al. (Phytochemisty, vol. 11, pages 2633 to 2634, 1972: “Some constituents of the leaves of Castanea sativa”) the following constituents have been identified in the leaves of Castanea sativa: waxes 0.1%, ursolic acid 0.2%, lupeol 0.4%, betulin 0.1%, aliphatic hydrocarbons 0.04%, fatty acids 1.58%.
According to Jones el et al. (Phytochemisty, vol. 23, pages 2666 to 2667, 1984: “A note on the ascorbic acid content of some trees and woody shrubs”) the ascorbic acid content in the leaves of Castanea sativa is 191.3+−24.1 mg per 100 g leaves.
The problem underlying the present invention is the need for substances that can be used in cosmetic applications.